A study of transition regions in InAsPSb/InAs heterostructures grown by MOVPE

A study by secondary-ion mass spectrometry of InAs x P y Sb 1– x – y /InAs heterostructures ( x > 0.55) grown by vapor-phase epitaxy for lattice-mismatched with substrates samples revealed a noticeable and extended (~800 nm) exponential variation of the As and P content ( y up to 0.12) across the layer thickness. The lattice mismatch calculated from the experimentally determined distribution of the As and P components was the strongest at the interface between the epitaxial layer and the substrate and decreased away from the heterointerface into the epitaxial layer.